The removal of hair from the human body has received considerable attention, both for medical and for cosmetic reasons. Various methods exist to remove unwanted hair. Conventional methods focus on mechanical removal and chemical depilation, whereby unwanted hair is removed once it has already appeared above the surface of the skin. Other methods involve the prevention, suppression or retardation of hair growth, by an alteration in the rate and character of hair growth.
Mechanical methods employed for depilation include tweezing, plucking, electrolysis, shaving and X-ray techniques. Tweezing and plucking are of limited utility because their use is confined to a localized area. Electrolysis and X-ray techniques are painful and require the use of expensive equipment, while shaving frequently stimulates rapid hair growth and leads to skin irritation.
Chemical depilatory compositions are effective in removing unwanted hair from larger areas on the skin. These compositions typically cleave disulfide bonds in hair keratin, causing the hair fiber to disintegrate. However, most chemical depilatory compositions are strongly alkaline, causing dermal irritation, particularly on sensitive facial skin.
At present, compositions generally called "waxes" are also used for depilation. These are applied to the skin in a molten state. On cooling and hardening, the wax enmeshes the hair it contacts. The wax is thin stripped from the skin, pulling out the enmeshed hair by its roots. Even though waxing is longer-lasting than other chemical methods, it is disfavored because of the tendency to cause irritation, swelling or possible burning.
Of the methods employed to alter the rate and character of hair growth, most involve the application of anti-androgens to control dermatological conditions associated with androgen-dependent disorders, such as female hirsutism. However, these methods have undesirable side effects such as systemic anti-androgen effects, teratogenecity and pituitary dysfunction and are, consequently, of limited use.
For the foregoing reasons, there is a need to develop a method which is efficacious, easily administered, non-irritating, long-lasting, and can regulate the growth of unwanted hair without allowing rapid return growth.
It is an object of the subject invention to provide topical compositions for retarding or preventing the growth of hair in mammalian skin.
It is a further object of the subject invention to provide such compositions which are gentler and less irritating to the skin than existing compositions.
It is also an object of the subject invention to provide methods for retarding or preventing the growth of hair in mammalian skin.